The Importance of Recombinant Allergens for Diagnosis and Therapy of IgE–Mediated Allergies

175

119

Allergenicity of plant and invertebrate N-glycans has been shown to be caused by the presence of two typical nonmammalian substitutions: an α(1,3)-fucose linked to the proximal N-acetylglucosamine and a β(1,2)-xylose linked to the core mannose. IgE antibodies against these carbohydrate structures are induced upon exposure to pollen or after insect stings, and result in extensive cross-reactivity to plant and invertebrate foods. These cross-reactive IgE antibodies have been shown to possess variable degrees of biological activity, but have never been convincingly shown to induce clinical food allergy. The most likely explanation for this lack of clinical relevance has to be sought in a combination of epitope valency and antibody affinity. In diagnostic tests, these antibodies are at the basis of many false-positive test results for food allergy. Recombinant technologies offer the possibility to produce allergens that do not carry IgE-binding glycans. Whether their absence or presence is of importance for the application of recombinant allergens in immunotherapy is still largely unknown.

Section: Recombinant Allergens For Application In Diagnostics and Immmentioning

confidence: 99%

Carbohydrate Epitopes and Their Relevance for the Diagnosis and Treatment of Allergic Diseases

Ree¹

2002

175

119

“…The general aspects of rAllergens for diagnostic and therapeutic use has recently been extensively reviewed elsewhere [30, 31, 32, 33, 34]. The rapid progress achieved in the fields of protein analysis and allergen cloning offers new opportunities for improved standardization of allergen preparations.…”

Section: Recombinant Allergensmentioning

confidence: 99%

Recombinant Allergens for Skin Testing

Schmid‐Grendelmeier¹,

Crameri²

2001

Skin testing is a basic diagnostic procedure widely used to explore immediate-type reactions to allergen preparations in vivo. Despite their reliability, if standardized extracts are used, skin tests suffer from limited reproducibility due to difficulties in preparing consistently standardized extracts from natural raw material. Starting from allergen-encoding cDNAs, large amounts of highly pure allergens with a high batch-to-batch consistency satisfying the quality requirements of medicinal products manufactured by recombinant DNA technology can be produced. These reagents are expected to be qualitatively superior to the commercially available allergen preparations used for the in vitro and in vivo diagnosis of allergic conditions. In this article the current literature available on skin testing with such recombinant allergens (rAllergens) is reviewed and critically analyzed. To date many different rAllergens of various pollens, moulds, mites, bee venom, latex and celery have been used in skin testing in more than 1,600 allergic and control individuals. Skin prick tests as well as intradermal skin tests with rAllergens prove to be highly specific and safe. The diagnostic sensitivity of single rAllergens is generally lower than those obtained with allergen extracts, but can be considerably increased by using rAllergen panels covering the most important allergenic structures present in a given complex allergenic extract. Moreover, quantitative skin testing with single rAllergens allows interesting insights into correlations between the in vivo and in vitro sensitization to a given allergen. In conclusion, skin testing with rAllergens offers a highly specific and safe additional diagnostic tool to elucidate patient- and disease-specific sensitization patterns which will be needed for the development of patient-tailored immunotherapeutic treatments.

“…It is a 17.4-kDa protein of which 42 isoforms are reported [8], but in extracts of pollen only about 9 isoforms were detected [7, 9, 10] with Bet v 1.0101 being the dominant allergenic isoform [11, 12]. Differences in allergenicity have been reported for some isomers of Bet v 1 [7, 13], including a lack of allergenicity for the Bet v 1.1001 (formerly Bet v 1l) isoform [14].…”

Section: Introductionmentioning

confidence: 99%

Year-to-Year Variation in Release of Bet v 1 Allergen from Birch Pollen: Evidence for Geographical Differences between West and South Germany

Buters

Kasche

Weichenmeier

et al. 2007

Background: The release of the aeroallergen Bet v 1 from pollen is a major determinant in the etiology of allergic airway disease due to birch pollen. Objective: We determined the release of the major birch pollen allergen Bet v 1 from pollen of birch trees growing in 2 different geographic regions in Germany for 2 consecutive years. Methods: Catkins were collected during pollination in 2002 and 2003 from 82 healthy trees in South (Munich) and West Germany (North Rhine-Westphalia). The release of Bet v 1 from pollen samples was determined by a Bet v 1-specific ELISA. Results: Pollen from South Germany released about 3 times more Bet v 1 than those from West Germany in both 2002 and 2003 (p = 0.034 and p = 0.007, respectively). This was independent of the number of pollen during the pollen flight season. In 2003, the release of Bet v 1 from pollen was more than 5 times higher than in 2002 in both regions (South Germany 6.1 times, p < 0.001; West Germany 5.4 times, p = 0.003). Conclusions: Despite large individual differences, there seem to be regional and year-to-year variations in Bet v 1 release from birch pollen. Therefore, the combination of pollen count and release of Bet v 1 from this pollen must be assessed to estimate Bet v 1 exposure reliably.